Structural Investigation of Diprotonated Glycine, Diprotonated Glycine Methyl Ester, and Monoprotonated Glycinoyl Fluoride

Glycine and its methyl ester hydrochloride were investigated in superacidic media HF/MF5 (M = As, Sb). The diprotonated species were obtained as [MF6]− salts (M = As, Sb). The colorless salts were characterized by vibrational spectroscopy, NMR spectroscopy, and single-crystal diffraction. Glycinoyl fluoride was isolated for the first time as a solid and characterized by vibrational spectroscopy, NMR spectroscopy, and single X-ray diffraction. Glycinoyl fluoride was investigated in the superacidic medium HF/MF5 (M = As, Sb). The salts of the diprotonated species were obtained and characterized by vibrational spectroscopy. The experimental data are discussed together with quantum chemical calculations at the M06-2X/aug-cc-pVTZ level of theory.